The compound 3-4-(butylthio)-1,2,5-thiadiazol-3-yl!-1-azabicyclo2.2.2!octane, described in U.S. Pat. No. 5,260,314 ('314), is a compound having muscarinic activity which is indicated for the treatment of Alzheimer's Disease, severe painful conditions, schizophrenia and glaucoma. As set forth in the '314 patent, 3-4-(butylthio)-1,2,5-thiadiazol-3-yl!-1-azabicyclo2.2.2!octane can be prepared in a solid form for oral use, in the form of suppositories for rectal administration, or in the form of sterile injectable solutions for parenteral use. A formulation for a typical tablet is provided; however, the patent does not suggest that it would be possible or desirable to prepare a transdermal 3-4-(butylthio)-1,2,5-thiadiazol-3-yl!-1-azabicyclo2.2.2!octane patch formulation.
Applicants have discovered that the transdermal 3-4-(butylthio)-1,2,5-thiadiazol-3-yl!-1-azabicyclo2.2.2!octane patch formulation of this invention provides surprising beneficial effects. The present invention provides a method for treating Alzheimer's disease and severe painful conditions with fewer side effects than are typically associated with muscarinic agonists like 3-4-(butylthio)-1,2,5-thiadiazol-3-yl!-1-azabicyclo2.2.2!octane. The transdermal formulation of this invention provides consistent dosage of the active ingredient, achieves sustained plasma concentration of the pharmaceutically active agent, and encourages patient compliance.